/**

    Let inheritance help with memory efficiency

*/

function SignalFire(ID, startingLogs){

    this.fireID = ID;

    this.logsLeft = startingLogs;

}

SignalFire.prototype = {

    addLogs: function(numLogs){

        this.logsLeft += numLogs;

    }

    lightFire: function(){

        alert("Whooosh!");

    }

    smokeSignal: function(message){

        if(this.logsLeft < this.message.length / 10){

            alert("Not enough");

        }else{

            this.lightFire();

            var x = this.message.length;

            for(var i = 0; i < x; i++){

                alert("((("+this.message[i]+")))");

                if(i % 10 == 0 && i != 0){

                    this.logsLeft--;

                }

            }

        }

    }

}

var fireOne = new SignalFire(1, 20);

var fireTwo = new SignalFire(2, 18);

var fireThree = new SignalFire(3, 14);

fireOne.addLogs(8);

fireTwo.addLogs(10);

fireThree.addLogs(14);

fireThree.smokeSignal("Goblins!");

//The addLogs method is found in one useful place, instead of being

//replicated across all signalFires.

/**

    Adding individual dom elements ain't always speedy

*/

//

//**BAD**

//

var list = document.getElementById("kotwList");

var kotw = ["Jenna Rangespike",

            "Neric Farthing",

            "Darkin Stonefield"];

for(var i = 0, x = kotw.length; i < x; i++){

    var element = document.creatElement('li');

    element.appendChild(document.createTextNode(kotw[i]));

    list.appendChild(element);

}

//appendChild(); function each time this list is appened, we access the DOM

//and cause an entire document reflow. Not as speedy as we'd like, especially

//if we list was huge...

/*

    Improve: Use a document fragment to insert additions all at once

*/

var list = document.getElementById("kotwList");

var kotw = ["Jenna Rangespike",

            "Neric Farthing",

            "Darkin Stonefield"];

var fragment = document.createDocumentFragment();

for(var i = 0, x = kotw.length; i < x; i++){

    var element = document.creatElement('li');

    element.appendChild(document.createTextNode(kotw[i]));

    fragment.appendChild(element);

}

list.appendChild(fragment);

/*

    Improve: declare variables as few times as possible

*/

//

//**GOOD**

//

var list         = document.getElementById("kotwList"),

    kotw         = ["Jenna Rangespike",

                    "Neric Farthing",

                    "Darkin Stonefield"],

    fragment     = document.createDocumentFragment(),

    element;

for(var i = 0, x = kotw.length; i < x; i++){

    element = document.creatElement('li');

    element.appendChild(document.createTextNode(kotw[i]));

    fragment.appendChild(element);

}

list.appendChild(fragment);

/**

    Efficient choices for string concatenation

*/

//

//**OK**

//

var knight = "Jenna Rangespike",

    action = " strikes the dragon with a ",

    weapon = "Halberd",

    turn = "";

turn += knight;

turn += action;

turn += weapon;

//It is ok because the code is short and clear

//

//**NOT GOOD ENOGUTH

//

var newPageBuild = ["<!DOCTYPE html>", "<html>", "<body>", "<h1>",

                    *** a hundred or more other html elements***,

                    "</script>", "</body>", "</html>"],

     page = "";

for(var i = 0, x = newPageBuild.length; i < x; i++){

    page += newPageBuild[i];

}

//

//**GOOD**

//

page = newPageBuild.join("\n");

//Using join is much faster than using '+=' and looks simple and clear!!

[Javascript]3. Improve you speed! Performance Tips的更多相关文章

  1. [Javascript]1. Improve you speed! Loop optimaztion

    /** Improve you loop code */ var treasureChest = { goldCoins: 10000, magicalItem : "Crown of Sp ...

  2. [Javascript]2. Improve you speed! Script Execution

    Let's take a closer look at how a browser retrieves and acts on scripts.modern browser can parallel ...

  3. Android 性能优化（19）＊代码优化11条技巧：Performance Tips

    Performance Tips 1.In this document Avoid Creating Unnecessary Objects 避免多余的对象 Prefer Static Over Vi ...

  4. 转载：Why using Single Root I/O Virtualization (SR-IOV) can help improve I/O performance and Reduce Costs

    Introduction While server virtualization is being widely deployed in an effort to reduce costs and o ...

  5. SQL Server performance tips

    Refer to: http://harriyott.com/2006/01/sql-server-performance-tips A colleague of mine has been look ...

  6. How To Improve Deep Learning Performance

    如何提高深度学习性能 20 Tips, Tricks and Techniques That You Can Use ToFight Overfitting and Get Better Genera ...

  7. 翻译--Blazing fast node.js: 10 performance tips from LinkedIn Mobile

    1.避免使用同步代码: // Good: write files asynchronously fs.writeFile('message.txt', 'Hello Node', function ( ...

  8. Performance tips

    HTML5 Techniques for Optimizing Mobile Performance Scrolling Performance layout-performance

  9. Json.NET Performance Tips

    原文: http://www.newtonsoft.com/json/help/html/Performance.htm To keep an application consistently fas ...

随机推荐

  1. C#用注册表开机自动启动某某软件

    代码如下: public static void chkAutoRun(bool isRun) { if (isRun)//开机自动启动 { try { RegistryKey runKey = Re ...

  2. Samba-ADS/WINBIND

    Samba Security = ADShttp://www.justlinux.com/forum/showt...hreadid=118288 Winbindhttp://www.justlinu ...

  3. 视图中的Layout使用(转)

    1.母板页_Layout.cshtml 类似于传统WebForm中的.master文件,起到页面整体框架重用的目地 1.母板页代码预览 1 <!DOCTYPE html> 2 <ht ...

  4. OOM总结

    本文主要信息是来自互联网,我只是自己做了一点总结和摘要. OOM发生的原因 简单的说通过不同的内存分配方式对不同的对象进行操作,会因为android系统版本的差异而产生不同的行为.主要是2.0和4.0 ...

  5. Solr导入数据库数据

    接Solr-4.10.2与Tomcat整合.1.在solrconfig.xml中添加数据导入节点,solrconfig.xml路径为D:\solr\data\solr\collection1\conf ...

  6. XML配置silverlight ，wcf 解析xml

    XML 代码: <?xml version="1.0" encoding="utf-8" ?><ChartSet  xmlns:xsi=&qu ...

  7. hdu find the safest road

    算法:多源最短路(floyd) 题意:每条通路有一个安全系数,求始点到终点的最大的安全系数并输出,如果没有输出What a pity! c++超时啊 Problem Description XX星球有 ...

  8. 用excel做一幅像素画

    开发背景 看到网上有人发教程,如何通过在excel里设置单元格颜色画一幅画,感觉手工做太复杂,就打算用程序实现一个. 开发运行环境 python 2.7 PIL xlsxwriter 用法 pytho ...

  9. 混入模式(max-in)实现继承

    混入模式并不是一种复制完整的对象,而是从多个对象中复制出任意的成员并将这些成员组合成一个新的对象. 实现如下: function mix(){ var arg,prop,child = {}; for ...

  10. ubuntu 下使用mysql

    第一步:安装mysql apt-get install mysql-server 第二步:设置允许远程登录 修改/etc/mysql/my.cnf(此文件为mysql的配置文件).将文件中的bindi ...